brother, tamerlan tsarnaev, was killed in a shootout with police. their mother insisted they are innocent, saying they were interested in islam but never talked about jihad. she says she believes to have been framed by police. the two brothers were caught on camera at the boston marathon carrying backpacks. police say they have images of one of the brothers setting his backpack down at the site of the explosion. the search has now begun for a possible motive. >> why did young man who grew up and studied here as part of our communities and country resort to such violence? how do they plan and carry out these attacks? and did they receive any help? the families of those killed deserve answers. >> president barack obama has promised to deliver those answers, stressing that the investigation continues. 157 people are confirmed dead and over 5000 injured after a powerful earthquake in southwestern china. the quake with a magnitude of 6.6 hit the province of sichuan. the epicenter was located in a rural, mountainous area near the city. the tremors were felt in chengdu about 150 kilometers away.